• The Journal of Advanced Prosthodontics
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• 제5권3호
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• pp.326-332
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• 2013

PURPOSE. The purpose of this study was to compare stress distributions of implant-supported crown placed in fibula bone model with those in intact mandible model using three-dimensional finite element analysis. MATERIALS AND METHODS. Two three-dimensional finite element models were created to analyze biomechanical behaviors of implant-supported crowns placed in intact mandible and fibula model. The finite element models were generated from patient's computed tomography data. The model for grafted fibula was composed of fibula block, dental implant system, and implant-supported crown. In the mandible model, same components with identical geometries with the fibula model were used except that the mandible replaced the fibula. Vertical and oblique loadings were applied on the crowns. The highest von Mises stresses were investigated and stress distributions of the two models were analyzed. RESULTS. Overall stress distributions in the two models were similar. The highest von Mises stress values were higher in the mandible model than in the fibula model. In the individual prosthodontic components there was no prominent difference between models. The stress concentrations occurred in cortical bones in both models and the effect of bicortical anchorage could be found in the fibula model. CONCLUSION. Using finite element analysis it was shown that the implant-supported crown placed in free fibula graft might function successfully in terms of biomechanical behavior.

• 음성과학
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• 제14권1호
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• pp.73-89
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• 2007

This study explored the perception of transplanted English prosody by thirty American and Korean, male and female listeners. The English utterances of various sentence types produced by Korean and American male speakers were employed to transplant the American prosody contours to Korean English utterances. Then, the thirty subjects were instructed to rate the transplanted prosodic components. Results showed that the interactions between the three factors (e.g., rater groups & transplantation types; transplantation types & sentence types; rater groups & transplantation types & sentence types) turned out to be meaningful. Both Americans and Koreans perceived the effectiveness of the combined effect of transplanted duration and pitch or duration and pitch and intensity. However, when perceiving individual prosodic components, Americans and Koreans showed different perceptual ratings. As for the overall prosody change, Americans perceived the change of intensity in a significant way but Koreans did not because intensity is not a crucial semantic factor in Korean. Americans rated the transplantation of duration alone as ineffective while Koreans rated otherwise. This was explained by the difference between English and Korean. The difference of perspective was also significant with different sentence types, especially with the three sentence types that had speech rates slower than other sentence types. A slower speech rate intensified the mismatch between the transplanted duration and the original pitch causing a negative impression on American listeners whereas this did not affect Korean listeners. Pedagogical implications of the findings are discussed.

• 터널과지하공간
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• 제2권2호
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• pp.199-211
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• 1992

Blasting vibrations of 3 quarries and 5 construction sites were measured and investigated with two reference data. Square and cubic root scaled distance were similar in fitness to peak particle velocity of individual blasting site, but the former is better fitted in total. It was suggested that the limit scaled distance for domestic surface blasting be 40kg/$\textrm{cm}^2$ for 10mm/s level and 60kg/$\textrm{cm}^2$ for 5mm/s level, which were lower than the OSM's regulation. Prevailing vibration components were in the order of radial, vertical and transverse directions. Prevailing vibration components were in the order of radial, vertical and transverse directons. Site factors K and m were 242 and -1.283 for all studied area, 357 and -1.348 for construction sites, 118 and -1.160 for quarries. Most prevailing frequency was in the range of 10~2Hz. Overlapping effect of delayed blasting vibrations were insignificant. Vibration history of delayed blasting was longer than simultaneous blasting, and it became longer as measuring distance increased. Wave form and predominant frequencies were more complicated for delayed blasting than instantaneous blasting. The influence of blasting scale and measuring distance were not significant to determine peak particle velocity equation.

• Asia pacific journal of information systems
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• 제23권4호
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• pp.151-175
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• 2013

This study investigates the potential components for academic research collaboration, and the factors that make it possible to achieve higher academic productivity. The components include collaboration factors and a collaboration model. We use two major collaboration factors to develop a framework for understanding the mechanisms that influence academic research collaborations: motivational factors and mediating factors. Motivational factors include self-motivation and trust whereas mediating factors are collaboration orientation and peer support. We analyze the effect for use of e-collaboration with research performance, reward, and satisfaction with e-research output. A survey of academicians was conducted, and by using the factor analysis and the structural equation model with SPSS 20 AMOS, we illustrate the possible influence of these factors on research performance and satisfaction. We discovered that both motivational and mediating factors play important roles on the success of academic research. This study offers several implications for academicians. We develop a parsimonious research model, which is related to e-collaboration in academic research. This unique model offers academicians to achieve good publication output from the research team. The motivational factor, self-motivation and trust, are important factors which has received positive impact of mediating factor collaboration orientation and peer support. Our research sheds light on the crucial factors for use of e-collaboration which offer the ultimate effect on performance and satisfaction with e-research output. Satisfaction motivates people to work more and more on the field of their interest, thereby influencing the performance of academicians. Rewards should be distributed according to performance of the individual, which will motivate the person to become more enthusiastic for his work of interest. Our evidence suggests that in understating the collaborative process, one must account for the context in which the collaboration occurs, the motivation of the collaborators, the scope and nature of the project, the roles and activities undertaken, and interpersonal processes such as trust. Researchers' motivations for engaging in collaboration were both instrumental and intrinsic.

• 융합경영연구
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• 제7권3호
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• pp.1-12
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• 2019

Purpose - This study aims to investigate the major capabilities of airline cabin crew to improve the performance of the organization by identifying how they are affected by turnover and customer orientation. Research, design, data, and methodology -The survey participants were limited to all airline cabin crew members in Korea to look at the component measurement items. To verify the validity of the questionnaire, the final questionnaire for this survey was prepared by modifying and supplementing the questionnaire by analyzing factors and validating the questionnaire through reliability verification Results - The analysis on the impact of personal capacity of the airline cabin crew on turnover revealed that some factors had an effect of the positive and the personal capacity of the airline cabin crew has a statistically positive effect on the customer orientation relationship, which is a sub-factor of the cabin crew Conclusions -The capacity of the cabin crew of the airline was defined and the components were established as technical capacity, knowledge capacity and expertise capacity. It was found that the intangible performance of the individual capabilities and customer orientation were very closely related. Airline cabin crew have verified the importance of good talent selection and capacity development training, which are essential requirements for securing the airline's competitiveness.

• 한국기후변화학회지
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• 제7권3호
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• pp.217-229
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• 2016

Increased evidences reveal that the global climate change adversely affect on the environment. Smart grid system is one of the ways to reduce greenhouse gas emissions in the electricity generation sector. Since 2013, Korea Electric Power Corporation (KEPCO) has installed smart grid station in KEPCO office buildings. The goal of this paper is two folds. One is to quantify the reduction in greenhouse gas emissions through smart grid stations installed in KEPCO office buildings as a part of pilot project. Among components of smart grid stations, this research focused on the photovoltaic power system (PV) and energy storage system (ESS). The other is to estimate the reduction in greenhouse gas emissions when PV is applied on individual houses. Results show that greenhouse gas emissions reduce 5.8~11.3% of the emissions generated through the electricity usage after PV is applied in KEPCO office buildings. The greenhouse gas emissions reduction from ESS is not apparent. When PV of 200~500 W is installed in individual houses, annual greenhouse gas emission reduction in 2016 is expected to be approximately $2.2{\sim}5.4million\;tCO_2-eq$, equivalent to 6~15% of greenhouse gas emissions through the electricity usage in the house hold sector. The saving of annual electricity cost in the individual house through PV of 200 W and 500 W is expected to be 47~179 thous and KRW and 123~451 thousand KRW, respectively. Results analyzed in this study show the environmental effect of the smart grid station. In addition, the results can be further used as guidance in implementing similar projects.

• 한국실내디자인학회논문집
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• 제27권3호
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• pp.136-144
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• 2018

The purpose of this study is to examined the unconscious response of the pupil in the observation toward the image in the eye-tracking experiments that target on a large complex cultural space. Twenty-five men participated in this experiment and the observation data were analyzed in seconds per minute on watching time. It could examine the unconscious response of information searching in the change of pupil size in the process of observing the space. The results could be defined as following several points. First, it was possible to outline the unconscious response characteristics of pupil by analyzing sudden changes in pupil size as total, cumulative, and individual. The response characteristics using frequency and time can be utilized as the analytical method to examine the degree of interest of spatial components according to the purpose of analysis in the future. Second, according to the over ${\pm}5%$ of cumulative variation rate on the pupil size change, during in the 60 seconds, the continuous pupil dilation was used 25.2 seconds in 8.8 rounds and the pupil reduction was used 18.0 seconds in 7.0 rounds. Third, when the variation rate of ${\pm}5%$ or more was regarded as the sudden changes on pupil size by individual variation, the pupil dilation was 7.2 rounds of 8.6 seconds and pupil reduction was 6.0 seconds in 5.0 rounds. This means that the pupil increases 9.3% in one expansion and decreases -8.5% in the reduction process. As regarding pupil changes as cumulative rate, it appeared high change rate on pupil reduction but it became higher on pupil dilation in individual.

• Nuclear Engineering and Technology
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• 제37권2호
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• pp.185-190
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• 2005

The Korea Institute of Radiological and Medical Sciences (KIRAMS) electron microbeam system has been built with its prototype components. The system is composed of an electron gun, a beam transport chamber, and a cell image acquisition and positioning stage. Each component has been upgraded through repetitive performance tests for various parametric arrangements. This paper presents the preliminary results of the performance test on the beam control and detection parts of the system.

• 전자공학회논문지S
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• 제34S권10호
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• pp.89-97
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• 1997

To extract time-varying evoked potential (EP), segement latency corrected average method is presented. This method is composed of three steps. First, adaptive filtering for reducing the effect of artifacts and removing background noise is performed. Next, validated intervals of individual segments are aligned, and latency components are detected by cross-correlation between the previously obtained and measured EPs within the intervals. Finally, after the detected latency component, responses of segments are groupe and averaged, the shole corrected EP signal is obtained. In the experiments, the resutls of the conventional methods including simple averaging, Woody's method, and peak component latency corrected averaging are obtained, the results compared with the present method for evaluating performance. Therefore, the presented method confirms that it reflects the latency variations of fundamental peaks and gets the improved EP.

• Journal of Power Electronics
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• 제12권3호
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• pp.509-517
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• 2012

This paper presents control strategies for cascaded H-bridge multilevel active power filters (APFs). A current loop controller is implemented using a proportional-resonant (PR) regulator, which achieves zero steady-state error at target frequencies. The power balancing mechanism for the dc-link capacitor voltages is analyzed and a voltage balancing controller is presented. To mitigate the picket-fence effect of the conventional FFT algorithm under asynchronous sampling conditions, the Hanning Windowed-FFT algorithm is proposed for reference current generation (RCG). This calculates the frequency, amplitude and phase of individual harmonic components accurately and as a result, selective harmonic compensation (SHC) is achieved. Simulation and experimental results are presented, which verify the validity and effectiveness of the devised control algorithms.